1. Technical Field
This invention relates generally to collapsible tubes used to contain and dispense fluids, and particularly to a method of forming a seal of laminated material on the dispensing orifice of a prior art tube formed of a collapsible tube wall of laminate material welded to a plastic head portion.
Collapsible tubes are packages in tube form having a dispensing orifice at one end of a deformable tube. The tube is deformed and collapsed by squeezing so that the contents are forced out the orifice. Such tubes are used to contain toothpaste, pharmaceuticals, cosmetics, personal care products, artists' pigments, adhesives, sealants and caulking materials, greases and lubricants, foods and condiments, and many other products. Collapsible tubes generally have a screw cap closure.
Such tubes are made of metal such as lead, tin and aluminum, and more recently of plastic and laminate materials.
Prior art collapsible tubes, particularly those of metal, often have a seal across the mouth of the tube. Such seals are generally used on medicinal products. The seal is pierced and deformed against the interior of the dispensing orifice before the contents are discharged. An unbroken seal assures the user that the product has not been tampered with or otherwise contaminated.
The seal also prevents the tube contents from leaking out prior to use. Also, the seal prevents any atmospheric contact with the tube contents, since the tube is sealed in an air-tight manner.
In use, the seal is pierced by, for instance, a point formed in the tube screw cap.
This invention is specifically directed to the method of forming a seal of laminate on the dispensing orifice of a prior art collapsible tube, wherein such tube has a rigid plastic head welded to a collapsible tube wall of a laminate material. Such laminate includes layers of plastic and metal foil.